Starting mechanism for continuous casting machine



Feb. 11, 1969 A. MICHELSON 3,426,835

STARTING MECHANISM FOR CONTINUOUS CASTING MACHINE Filed May 11, 1966 Sheet of 5 INVENTOR. I ANATOL MICHELSON ih ww, g 204,

ATTORNEYS Feb. 11, 1969 A. MICHELSON 3,426,835 STARTING MECHANISM FOR CONTINUOUS CASTING MACHINE Filed May 11, 1966 Sheet 2 of a $4--" l5 1 14 Lg] M 23 6| E N [F 777111] wu..nul-.a- I

48 1 I I TEE E 1 D 1 4. L l w 2 33 0 34 T r 0 3 74 E 7 F 1 6| so 49 2O 513 I 26 INVENTOR. I 0 43 I ANATOL MICHELSON BY 46 O w fla ww,

ATTORNEYS Feb. 11, 19% A. MICHELSON STARTING MECHANISM FOR CONTINUOUS CASTING MACHINE Fi led May 11, 1966 Sheet INVENTOR. ANATOL MICHELSON ATTORNEYS Feb. 11, 1969 A.MICHEL$ON STARTING MECHANISM FOR CONTINUOUS CASTING MACHINE Sheet Filed May 11, 1966 INVENTOR ANATOL MBCHELSON ATTORNEYS Feb 11, 1969 A. MICHELSON STARTING MECHANISM FOR CONTINUOUS CASTING MACHINE Sheet Filed May ll, 1966 m T N E V W ANATOL MICHELSON ATTORNEYS United States Patent 3,426,835 STARTING MECHANISM FOR CONTINUOUS CASTING MACHINE Anatol Michelson, Glenolden, Pa., assignor to E. W. Bliss Company, Canton, Ohio, a corporation of Delaware Filed May 11, 1966, Ser. No. 549,232

U.S. Cl. 164--274 2 Claims Int. Cl. B22d 11/08; F16b 9/00 ABSTRACT OF THE DISCLOSURE A starting mechanism for use with a continuous casting machine including a mold into which molten metal is poured at one end and an ingot emerges from the other. The mechanism includes a flexible carrier member chainlike in construction and including a first link connected to a series of interconnected, independently movable links. A starting head, receivable in the mold to provide a temporary bottom therefor, is releasably connected to the carrier means by a connecting means including a recess in the starting head which is adapted to receive an end portion carried on the first link. In the recess a ball set is formed and carries a plurality of locking balls each freely and radially movable between locked and unlocked positions. Operating means are provided including a disconnect rod slidably movable longitudinally of the first link within the end portion for preventing radial movement of the balls from the locked to the unlocked position prior to reaching a predetermined position of withdrawal. Cam means extend outwardly of the first link for contact with a cam engaging means at the predetermined position of withdrawal to move the disconnect rod to a release position.

The present invention relates to a starting mechanism for use in casting continuous metal rounds, ovals, squares, slabs or the like hereinafter referred to generally as ingots.

More particularly, the invention relates to a new and improved starting mechanism for a continuous casting machine having a flow-through mold located in an elevated position. The ingot is withdrawn initially from the mold along an arcuate path so as to reduce the overall casting height and then is straightened into an horizontal path prior to cutting.

In order to begin a continuous casting run, a temporary bottom is provided for the mold. The temporary mold bottom, or starting head, is in the form of a bar having a transverse and vertical cross section adapted to fit the mold cavity. In order to support the starting head and move it to and from the mold during the starting process, a long, flexible carrier chain is provided. A curved conveyor is positioned to guide the carrier chain to and from the mold and to support the ingot in its arcuate descent from the mold once casting commences. Once the carrier chain is completely withdrawn from the curved conveyor, it is disconnected from the starting head which continues on with the ingot to the straightening rolls while the carrier chain is moved out of the way.

Due to the length and weight of the carrier chain, merely moving it out of the way presents several problems. Heretofore, considerable floor space for storage of the carrier chain and massive handling equipment for moving it to and from the mold has been required. hi the prior art, the chain is stored in a long runout channel extending in a horizontal direction generally parallel to the ingots path of travel. A motor driven sprocket meshing with the links of the chain may be used for driving it out of the channel and into the curved conveyor at the start of a run.

This problem is overcome with the present invention in which a flexible starting mechanism is withdrawn by a ICC takeup device comprising a trackway diverging away from the ingot path Which receives the starting mechanism and guides it out of the path of the oncoming ingot along a course which involves a substantial change of direction to that taken by the ingot, the arrangement permitting maximum utilization of available space for the storage of the starting mechanism between casting runs.

In accordance with this aspect of the invention, the trackway includes a series of support rolls extending upwardly and rearwardly for receiving the carrier member and storing it in a semi-coiled form. A motor driven drum is located adjacent the inner end of the coil and a cable wound on the drum is connected to the carrier member. A driver engages the carrier member for moving it from the stored position to the mold causing the cable to unwind against the restraining torque of the drum.

Further in accordance with this aspect of the invention, the takeup device includes a trackway embodied in the form of a channel member which extends downwardly and rearwardly underneath the mold.

Another problem associated with the prior art starting mechanisms has been in disconnecting the carrier chain from the starting head and ingot within the short space provided for disconnection. In some instances, this has been done manually by unfastening the first link of the carrier chain while the ingot is moving, however, this is unsatisfactory, mainly because any delay in disconnection will result in severely damaging the casting machine and interrupting the casting process.

Moreover, there is a hazard and great inconvenience to personnel associated with manual disconnection, particularly in multistrand machines where access to inner ingots is very difficult.

Prior art automatic disconnection devices have proved unsatisfactory, particularly in curved casting installations. These devices are of two kinds, generally, first; there is the type having a rigid joint, without any moving parts, which locks and unlocks the starting head by a turning action. This is not feasible for machines with a curved ingot path however, because the curved starting bar used with such machines cannot be turned, and second; there is the type incorporating hinges, springs and sliding-fit parts, or the like, requiring close tolerances. These latter devices are too sensitive to casting conditions such as very high surrounding temperatures, steam, dirt, falling scale, huge forces, etc., and moreover, the operating mechanism in such devices requires considerable space. The usual width is a minimum of about 6", which prevents its use in starting mechanisms for the casting of small ingots or narrow slabs.

Therefore, in accordance with another aspect of the invention, one of its main purposes is to provide a starting mechanism including a disconnection device housed in the carrier member, the operation of which is adapted to separate the forward end of the carrier member from the starting head and ingot at the moment during withdrawal that disconnection is desired. The device includes as its operating mechanism, a plurality of radially movable balls which provide the only connecting details locking the starting head and carrier member. This arrangement requires an absolute minimum of space and can be accommodated in starting mechanisms intended for ingots or slabs of any useful, small size. Also there is practically no chance that the operating mechanism will become jammed or inoperative at high surrounding temperatures or due to dirt or large forces.

Therefore, one object of the present invention is to provide a starting mechanism which occupies a minimum of plant floor space and which can be more closely integrated with existing casting machines.

Another object of the present invention is to provide a starting mechanism employing a carrier member which can be disconnected from the starting head without requiring manual servicing and which can be readily moved out of the way so as not to interfere with the withdrawal of the ingot.

Another object is to provide a quick acting and reliable disconnect device mounted in the end of the carrier member which operates automatically upon movement of the carrier member beyond a predetermined position during withdrawal.

Other objects, uses, and advantages of the invention will become apparent from the following detailed description and drawings wherein like parts are identified by like numerals wherein:

FIGURE 1 is a front elevational view of a continuous casting apparatus embodying the invention;

FIGURE 2 is a fragmentary sectional view showing a flow-through mold with the starting head positioned therein at the start of a casting run in the continuous casting apparatus of FIGURE 1;

FIGURE 3 is a fragmentary sectional view showing the withdrawal and straightening rolls of the continuous casting apparatus of FIGURE 1;

FIGURE 4 is a fragmentary sectional view similar to FIGURE 3 showing the position of one end of the carrier chain after disconnection;

FIGURE 5 is a side view of the first link of the carrier chain according to the preferred embodiment of the invention showing the starting head releasably fastened thereto;

FIGURE 6 is a fragmentary sectional view taken on the line 6-6 of FIGURE 5;

FIGURE 7 is a fragmentary sectional view with parts broken away and taken on the line 7--7 of FIGURE 6;

FIGURE 8 is an offset cross-sectional view with parts broken away and taken along line 88 of FIGURE 6; and

FIGURE 9 is a front elevational view of a modified form of continuous casting apparatus embodying the invention.

Referring more particularly to the drawings which are for the purpose of illustrating specific embodiments of the invention only and not for the purpose of limiting same, FIGURE 1 shows a continuous casting machine of the type wherein an ingot I is formed in a flow-through mold M and conveyed through an arcuate path of travel whereupon it is straightened and subsequently cut into desired billet lengths. Mold M is curved in vertical cross section so that the ingot I emerges and follows an arcuate path primarily to reduce the mold to floor height which enables the overall height of the casting machine to be reduced. The mold may be straight, however, and the ingot bent from a vertical position through an arc of 90 degrees and then restraightened if desired for similar reasons.

A ladle A of the bottom pour variety is adapted to supply molten metal to a tundish B. The ladle A is supported above the mold M on a carriage which has wheels 10 which travel on rails 11 so that ladle A may be moved out of position when empty and a full ladle moved into place. The tundish B has a refractory lining which defines a closed pouring chamber 12 and an open basin 13 communicating with each other through a port 14 (FIGURE 2). The pouring chamber 12 has a nozzle 15 for discharging a metered flow of molten metal into the mold M.

Located immediately below the mold M is a curved conveyor or roller apron D adapted to convey the ingot I formed by the mold M along an arcuate path of travel from a substantially vertical position to an horizontal position when straightened. The roller apron D passes through cooling chambers and 21 which assist in the cooling of the ingot. Cooling water is supplied on the ingot surface by means of spray jets I located between rolls 24, 26 of roller apron D. The steam is extracted from the chambers 20', 21 by means of an exhaust duct 22 and worked water is abducted through drain piping 23. Located at the end of the roller apron D is a withdrawal and straightening unit F for the withdrawal and straightening of the ingot I so that it follows a linear horizontal path of travel to a cutoff device G where it is cut into suitable billet lengths. The unit F includes withdrawal rolls 40, 41, which are driven by a suitable drive means (not shown).

In accordance with the preferred embodiment of the invention, the starting mechanism of FIGURE 1 includes a carrier chain E composed primarily of curved, interconnected links 20 adapted for travel through the roller apron D. The carrier chain E is of sufficient length to extend through the entire length of the roller apron D from mold M to withdrawal rolls 40 and 41. The links 20, first link 33 and starting head 34 are each curved in the form of segments of a circle and have the same radius point as the roller apron D and mold cavity. If a straight mold is used, the starting head 34 is also straight and the links may remain curved but should not be of greater length than the spacing of the conveyor support rolls associated with such straight mold.

It should be noted that the trailing end of the carrier chain E is fastened to a pull cable 31 which is wound on a motor driven drum 32 which serves to retract the carrier chain E from the roller apron D in cooperation with the withdrawal rolls 40, 41. More particularly, the drum 32 pulls the chain onto a trackway including overhead rollers 36. The cooperation of the trackway and particularly rollers 36 and drum 32 draw the chain E into a semi-coiled configuration elevated above the main floor to accomplish a considerable saving in space.

As best shown in FIGURE 3, the lower withdrawal rolls 41 are mounted on a bracket 42 connected to an hydraulic cylinder 43 which serves to press the rolls 40, 41 against the carrier chain E or ingot I to provide the necessary frictional engagement to achieve uniform withdrawal. Also included in the assembly F are straightening rolls 44, 45. The roll 44 is relatively moveable between a carrier chain guiding position shown in FIGURE 3 for guiding the carrier chain E during its withdrawal from the conveyor D, and a straightening position shown in FIGURE 4 wherein the roll 44 applies straightening force to the ingot I. The straightening roll 45 is mounted in fixed position. Power rolls 44, 45' drive the chain E toward the mold at the start of a run, but during withdrawal these rolls are separated to allow free passage of the chain as will be described more fully hereinafter.

Movement of the straightening roll 44 and support roll 49 is provided for by means of a worm drive mechanism 46 which operates a screw 47 connected at its outer end to link 48. The link 48 is pivotally connected at one end to the frame of the assembly F and carries the roll 44 at its opposite end. Support roll 49 has as its principal purpose the supporting and guiding of the under side of the carrier chain B when the straightening roll 44 is in the position shown in FIGURE 3. Also mounted on the assembly F are two vertically mounted cam rollers 53 indicated in dashed lines in FIGURES 3 and 4 and which will be more particularly described below.

Referring now to FIGURES 5-8, there is shown the connection between the starting head 34 and the first link 33 of the carrier chain E whereby a means is provided for automatically disconnecting these parts as they pass through the assembly F. In accordance with this aspect of the preferred embodiment of the invention, mounted at the end of the starting head 34 is a bolt head 60 which becomes embedded in the starting end of the ingot I when the starting head 34 is inserted in the mold to provide a bottom as shown in FIGURE 2. The bolt 60 also serves to fasten a floor plate 61 to the starting head 34 which is separated therefrom by means of an absestos insulating gasket 62 as best shown in FIGURE 6. The starting head 34 has a cylindrical recess 63 formed therein which receives a boss 64 projecting from the end of the first link 33. The first link 33 has a central bore 65 which slidably receives a disconnect rod 70. The boss 64 has radial bores drilled therein which receive locking balls 71. When the disconnect rod 70 is in its connected position as shown in FIGURE 6, the balls 71 bear inwardly against the cylindrical surface of the end of the disconnect rod 70 and are thus forced radially outward into ball seats 72 formed in the wall of the recess 63. This serves to lock the starting head 34 to the first link 33. The disconnect rod 70 is slidable between the position shown in FIGURES 5 and 6 wherein the end of the rod maintains the locking balls 71 in the ball seats 72 on the starting head 34 and a second position shown in dashed lines in FIGURE 6 wherein a circumferential groove 68 formed in the end of the disconnect rod 70 is adjacent to the balls 71 and permits the balls to move radially inward out of the locking position. In this second position, the boss 64 is free for release from the chamber 63 of the starting head 34.

Sliding movement of the disconnect rod 70 is provided for by means of toggles 75 connected to the inner end of the disconnect rod 70. Two pairs of toggles 75 are provided, each consisting of a cam lever 73 and a connecting lever 74. The cam levers 73 are pivotally connected at one end to the first link 33 and at the other end to the connecting levers 74. The connecting levers 74 are connected at their opposite ends to the disconnect rod 70. The cam levers 73 have a cam portion which normally extends outwardly from the sides of the first link 33 as shown in FIGURE 6. When the cam portions engage the cam rollers 53 mounted in the asembly F, they are forced inwardly to operate the toggles 75 and thus force the dis connect rod 70 forward to release balls 71 from their locking positions. This serves to disconnect the first link 33 from the starting head 34.

The cam levers 73 and connecting levers 74 are mounted in a lateral slot 76 formed in the first link 33 (FIGURE 7). Extending through the slot 76 are two pivot pins 77 which serve as a pivotable support for the cam levers 73. The other end of the cam levers 73 is pivotally connected to the connecting levers 74 by means of a hinge pin 78. The connecting lever 74 is pivotally attached to an arm extending rearward from the disconnect rod 70 by means of a hinge pin 79. In order to provide access for assembly and connection of the toggle levers to the disconnect rod 70, a vertical bore 80 is provided in the first link.

OPERATION In operation, the carrier chain E is initially positioned in the roller apron D so that the starting head 34 which is connected to the first link 33 is located in the mold M to provide a temporary bottom therefor as shown in FIGURE 2. Molten metal is then poured from the ladle A into the tundish B and in turn through the nozzle 15 into the cavity of the mold M. As the molten metal is cooled in the mold, an outer solidified skin is formed and the carrier chain E is actuated by withdrawal rolls 40, 41 to begin the withdrawal of the starting head 34 in accordance with a prescribed casting rate. The withdrawal of chain E by rolls 40, 41 continues until the starting head 34 reaches approximately the position shown in FIGURES 1 and 3, the ingot I having been drawn through the cooling chambers 20 and 21 to cool the metal so that it has solidified throughout, at the lower end at least, but is still substantially at the solidification temperature. As the cam levers 73 of the first link 33- engage the cam rollers 53 located on the assembly F, the toggles 75 operate to force the disconnect rod 70 forward. This shifts the end of the disconnect rod 70' relative to the locking balls 71 and positions the circumferential groove 68 adjacent to the balls 71. As provided by the invention, at the same time the drum 32, which is being driven at the speed of withdrawal rolls 40, 41, is now shifted to a higher speed. Since the power rolls 44, 45 are not touching the chain at this time, the drum 32 exerts a positive retraction force which disengages the first link 33 and quickly disconnects it from the starting head 34. Thus the chain E is withdrawn from the path of travel of the ingot I to the stored position shown in FIGURE 4. The end of the chain is pulled by the cable 31 which is being wound up on drum 32. Overhead conveyor rolls 36 cooperate to loop the chain back upon itself as shown in FIGURE 1, thus providing midair storage of the chain when not in use. At the start of a run, power rolls 44', 45' are moved against the chain E to feed it from the conveyor rolls 36 against the slight restraining pull of cable 31 and drum 32.

After disconnection, the straightening roller 44 is repositioned as shown in FIGURE 4. Thus the roller 44 exerts a bending force upon the oncoming curved ingot I in cooperation with the roller 45 to change the path of travel of the ingot from a curved to a linear horizontal direction. The starting head 34 remains connected to the starting end of the ingot I but is separated at a later stage after the ingot reaches the cutoff device G where it is cut into suitable billet lengths.

FIGURE 9 FIGURE 9 shows a modified form of the invention wherein like parts are indicated by like numerals and other parts have corresponding numerals as used in identifying similar parts of the apparatus of FIGURES 1-8 but with the addition of a prime symbol. This form of the invention differs from that of FIGURES 1-8 primarily with respect to the storage method of chain E. Instead of storage accommodation above the ingot path, the chain E is stored underneath. In this case, the power rolls 44", 45" continuously engage the chain E which is guided by a channel H. This construction is shown primarily to indicate a modification of chain storage facility which may be more suitable for some specific applications. In all other respects, the advantages are similar with those of the apparatus of FIGURES 1-8. For example, the rolls 44", 45" may be provided with a two-speed drive so that the chain E' can be quickly disconnected and moved out of the way of the oncoming ingot I, thus performing a function similar to that of drum 32 in the preferred embodiment.

Carrier chains of different sizes may, of course, be used to adapt the apparatus to various cross-sectional sizes of metal ingots. While the specific ingot crosssection shown is substantially square, it will be readily apparent that other cross-sections may be provided for such as circular, rectangular, etc. Chain E is preferably composed of straight links which are shorter than the space between three support rolls 26 but greater than the space between two. The changing of each carrier chains E, E may be easily accomplished by merely removing it by crane either from supporting rolls 36, (FIGURE 1) or from the rear of channel H (FIGURE 9), and substituting another carrier chain having the desired transverse cross-section.

While the invention has been described with reference to specific embodiments, changes and modifications in the embodiments shown may, of course, be made without departing from the invention as defined by the appended claims except insofar as limited by the prior art.

Having thus described my invention, I claim:

1. A starting mechanism for use with a continuous casting machine including a mold into which molten metal is poured at one end and an ingot emerges from the other comprising:

a flexible carrier member adapted to be moved along a curved path to and from the mold,

a starting head releasably connected to the front end of the carrier member and receivable in the mold to provide a temporary bottom therefor during the start up of a casting run,

means for disconnecting the carrier member from the starting head including a plurality of locking balls each freely and radially movable between locked and unlocked positions,

operating means for excluding radial movement of the balls from the locked position to the unlocked position prior to reaching a predetermined point of withdrawal,

the carrier member being chain-like in construction and including a first link connected to a series of interconnected, independently movable links, the end portion of the first link being adapted to be received in a recess formed in the starting head and including a disconnect rod slidably movable longitudinally of the first link within said end portion,

a ball seat formed in the inner wall of said recess,

a circumferential groove formed in the disconnect rod located rearwardly of said balls in the locked position whereby longitudinal movement of the rod positions the circumferential groove beneath the balls permitting movement radially and inwardly thereof to the unlocked position to disconnect said starting head, and,

a cam means connected to the first link for moving the disconnect rod upon contact with a cam engaging means at the predetermined point of withdrawal.

2. A starting mechanism for use with a continuous casting machine including a mold into which molten metal is poured at one end and an ingot emerges from the other comprising:

a flexible carrier member chain-like in construction and including a first link connected to a series of interconnected, independently movable links;

a starting head receivable in the mold to provide a temporary bottom therefor during the start up of a casting run; and,

releasable connecting means for connecting said starting head to said flexible carrier member, said connecting means including a recess formed in said starting head,

an end portion carried on said first link and adapted to be received in said recess,

a ball seat formed in said recess and carrying a plurality of locking balls each freely and radially movable between locked and unlocked position,

operating means including a disconnect rod slidably movable longitudinally of the first link within said end portion for preventing radial movement of the balls from the locked position to the unlocked position prior to reaching a predetermined point of withdrawal,

recess means formed in the disconnect rod located rearwardly of said balls in the locked position whereby longitudinal movement of the rod positions the recess means beneath the balls permitting movement radially and inwardly thereof to the unlocked position to disconnect said starting head,

a cam means carried in the first link and extending outwardly thereof for moving the disconnect rod upon contact with a cam engaging means at the predetermined point of withdrawal.

References Cited UNITED STATES PATENTS 1,618,851 2/1927 Thunberg et a1. 24-123 3,002,368 10/1961 Moberg 85-5 X 3,043,563 7/1962 Gray et al. 85-5 X 3,274,653 9/1966 Foldessy et al 164-274 3,305,899 2/1967 Saunders 164-412 3,324,934 6/1967 Hess et al. 164-274 3,344,844 10/1967 Reinfeld et al. 164-274 3,351,124 11/1967 Hess 164-82 XR FOREIGN PATENTS 1,213,962 4/ 1966 Germany.

717,056 10/ 1954 Great Britain.

729,359 5/ 1955 Great Britain.

929,478 6/ 1963 Great Britain.

945,970 1/ 1964 Great Britain.

WILLIAM J. STEPHENSON, Primary Examiner.

R. SPENCER ANNEAR, Assistant Examiner.

US. Cl. X.R. 287-20 

